distribute	reads
0-500	0
500-800	30
800-1000	15
1000-1200	6
1200-1400	10
1400-1600	3
1600-1800	6
1800-2000	1
2000-2200	3
2200-2400	4
2400-2600	0
2600-2800	0
2800-3000	1
>3000	4
